Extendable antenna having pivotable and displaceable elements



March 13, 1962 o. SAUPE ETAL EXTENDABLE ANTENNA HAVING PIVOTABLE AND DISPLACEABLE ELEMENTS Filed July 25, 1958 S e R m N m w P Q m Md E Q 5 w \n/ I: l A 0 a ATTORNEY United States Patent 3,025,088 EXTENDABLE ANTENNA HAVING PIVOTABLE AND DISPLACEABLE ELEMENTS Otto Saupe, Esslingen (Neclrar), and Siegfried Schiine,

Koln, Germany, assignors to Richard Hirschmann Radiotechnisches Work, Esslingen (Neckar), Germany, a

firm

Filed July 25, 1958, Ser. No. 751,015 3 Claims. (Cl. 287-54) The invention relates to an extendable antenna comprising a plurality of rod-shaped elements that are pivotally secured to a support. In packing conventional antennas of this type, which are primarily used for radio or television reception, it is customary to dispose the swingable elements parallel to the supporting structure. Before the antennas are mounted, it is only required to swing the elements into a vertical position with respect to the horizontally elongated support and secure them in place with the aid of a screw. In their folded position the outermost elements extend approximately half their length beyond the supporting base. This has distinct disadvantages, in that the containers, ordinarily used for packing such preassembled antennas, must be longer than the antenna supporting base by a length approximately equal to that of an antenna element (reflector or director).

However, for the shipment and storage of the antennas it is important that they occupy as small as space as possible. In order to avoid such an additional container length it has, therefore, become desirable to provide conventional antennas of a type wherein the two outermost elements (the reflector and the last director) are detachable from the supporting base so that they can be separately placed in the container. A three-membered antenna of the foregoing type can hardly be called a pre-assembled one because only the dipole reception remains pivotally connected with the base.

By way of contrast, the antenna in accordance with the present invention can be packed in a container which need not be substantially longer than the antenna supporting structure without any necessity of detaching the outermost antenna elements. With this in mind, at least the outermost elements are longitudinally displaceable and fastenable.

A particularly advantageous embodiment of the antenna according to the present invention comprehends rodshaped elements that are capable of being displaced only when the pivotal retaining means are loosened and are secured in place when the pivotal retaining means on the antenna supporting base are tightened up. It is advantageous to have the pivotal retaining means consist of two clamping dogs capable of grasping the antenna element. These dogs are mounted in a hinge-like member for reciprocal rotation about an axis lying adjacent to the antenna element and parallel thereto and are capable of being drawn together on the side of the antenna element that lies opposite to said axis for clamping it in place, preferably with the aid of a screw by means of which the entire retaining arrangement is, at the same time, secured to the support.

Since this clamping screw and, therefore, the rotational axis of the retaining means does not extend through the axis of the antenna element, it appears that the antenna element could be displaced on the support to a distance equal to twice the space between these two axes, depending upon whether the antenna element, which initially lies parallel to the support, is to be pivoted from the left or the right into a position perpendicular with respect to said support. This would permit mounting the antenna elements at different distances from one 3,ll25,088 Patented Mar. 13, 1962 another. However, this must be avoided, since the reception characteristics of such antennas generally undergo considerable changes with the spacing of its elements. With this in mind, the antenna according to the present invention is provided with simple means that'prevent any such objectionable variation in the assembly thereof.

According to a preferred embodiment, for example, the antenna supporting structure is positioned in a recess of the pivotal retaining means when the antenna element is pivoted to a position vertical to the support.

On one side of the aforesaid recess there is provided a raised stop which can not be turned beyond the antenna support since the extent of the spacing of the pivotal retaining means from the antenna support is further limited, for example, by a rivet head at the free end of the clamping screw.

According to a particularly advantageous embodiment of the antenna according to the present invention, the displaceable rod-like elements are held by a catch or click-stop device in their operative position which, in this Way, remains positively and reliably secured. Moreover, the displaceable elements can be moved into their operative position even when they are still folded parallel to the support. In the latter condition, the antenna can be moved onto the roof through a small opening in the roof between the rafters and the roof batten. On the roof it is merely required to pivot the elements to the position vertical to the supporting structure and then tighten them in place. The ease of installment achieved in this manner has been found very significant in practice.

The catch arrangement alone would ordinarily suifice for holding the various displaceable elements in operative position. However, it is better for the sake of increased safety if the displaceable elements are clamped in place with the retaining means as the latter is drawn together. Additional advantageous features of the antenna according to the instant invention will become apparent from the description herein and the accompanying drawings in which one form of antenna is shown for illustrative purposes only.

FIG. 1 is a view of a known antenna having swingable rod-shaped elements in folded position, whereas FIG. 2 shows an antenna according to the present invention also in folded position.

FIG. 3 shows a view from below of the element retaining means according to one embodiment of the invention.

FIG. 4 is a cross-section through the center of this retaining means.

The antenna according to FIG. 1 may comprise a support 1 and a retaining means 2 for associating therewith a collapsible dipole 3, a rod-shaped reflector 4 and a similar rod-shaped director 5, for pivotal movement about the bolts upon which the wing nuts 6, 7 and 8 are mounted. FIG. 1 shows the antenna elements 3 to 5 lying parallel to the supporting structure. Upon being pivoted to a perpendicular position with respect to support 1 they can be held in place by tightening screws 6 to 8, since the support 1 is then in a recess of the pivotal retaining means 9 to 11. The shipping of the folded antenna requires a container that is longer than the antenna supporting structure by a length approximately equal to that of one of the antenna elements 4 or 5.

The antenna according to the present invention, which is shown in FIG. 2, with its elements also lying parallel to the supporting structure, has a similar support 1 and a similar collapsible dipole 3 which is also pivotally fastened at about the center thereof. However, the elements that are pivotally secured to the ends of the support, i.e., the reflector 12 and the director 13, possess the additional feature of being longitudinally displaceable in their pivotal retaining means and fastenable therein in any suitable 3 way. The elements 12 and 13, in their condition for shipment or storage shown in the drawing, are displaced towards the center of the support until a stop provided at the ends thereof rests against the retaining means 14 and 15. As clearly shown in these drawings, the container for the antenna according to FIG. 1 must be almost twice as long as the container for the antenna of the present invention according to FIG. 2.

The element-retaining means in the antenna of the present invention is shown in FIGS. 3 and 4 as comprising two clamping dogs 16 and 17 that embrace the rod-shaped antenna element 18 represented in this case as a tube. The two clamping dogs are mounted in a hinge-like member for reciprocal rotation about an axis lying adjacent to the antenna element 18 and parallel thereto. The hinge-like joint, shown in the drawing by way of example, is composed of a projection 19 of dog 17 which is urged into engagement with a recess in the shoulder 20 integral with dog 16. A wing screw 22 is screwed onto a thread which is cut into the opposite end 21 of clamping dog 16, upon being inserted through a bore in the free end 23 of dog 17 and two bores in the walls of antenna support 24, the latter being provided as a rectangular hollow body. The drawing shows the retaining structure in a completely opened condition suspended beneath the antenna support 24. The antenna element 18 is pivoted to a position perpendicular to the support. When the wing screw 22 is screwed into the thread at the end 21 of dog 16, the two clamping dogs 16 and 17 are pulled against each other and against the antenna support 24. In so doing, the antenna element 18 which is loosely positioned for longitudinal movement between the opened clamping dogs, is tightly clamped in place and is also immobilized in its position vertical to support 24 since the latter is secured in a recess within clamping dog 17. The edges of this recess, of which only one is shown in the sectional view (FIG. 4), embrace the rectangular supporting structure at the side thereof. The edge of the recess seen in FIG. 4 has a lower portion 25 and a higher portion 26. The other edge of the recess, which is not shown in the drawing, is generally only as high as the lower portion of the recess viewed in the drawing. As seen in FIG. 4, the higher edge portion 26 forms a stop which can not be turned underneath the support since the clamping screw 22 is prevented from being drawn out farther at its lower end by the provision there-on of rivet head 27. Only the lower edge portion and the second, also lower, edge portion of the recess that is not seen, can be turned underneath the support when the opened retaining structure is turned from its slanting position, shown in the drawing, to a position parallel to the support.

By the provision of stop 26 and rivet head 27 on screw 22, one obtains that the antenna element 18 can only be pivoted in one direction of rotation from a position par? allel to the supporting structure to a position vertical to said structure and inversely. A wire spring 28 bent the shape of a U is inserted into two bores in clamping dogs 16 and 17. The bores, each having a diameter somewhat larger than the diameter of wire spring 28, are provided in both clamping dogs in such a way that the two legs of U-spring 28 extend, in the neighborhood of the slit between the two clamping dogs, into the space defined by these and antenna element 18. The latter is provided centrally thereof with a groove 29 extending around its circumference. The legs of U-spring 28 will come to rest in this groove so as to resiliently lie against antenna element 18 when this element is moved into its operative position.

The back of the U-spring is placed in a slot 30 of clamping dog 16 and is retained therein by crimping of the slot edges. A stop is provided at both ends of antenna element 18 in order to prevent it from completely sliding out of the retaining means. This can also be accomplished by the insertion of a crosspiece in the form of a 4 pin, the ends of which can be riveted in the shape of heads 31 (FIG. 3).

We claim:

1. Extendable antenna comprising a support, a plurality of rod-shaped elements extending in their operative position perpendicularly from said support, retaining means embracing said rod-shaped elements in which at least those of the elements that are mounted at both ends of said support are displaced longitudinally and fastening means lying adjacent to said rod-shaped elements with which said retaining means are secured to said support in such a way as to permit pivoting but not forward sliding thereof and which serve at the same time in operative position to clamp said rod-shaped elements in said retaining means and the latter to said support, whereby the said retaining means have recesses which receive said support when said rod-shaped elements are pivoted to their operative position, and means provided on said retaining means and on said rod-shaped elements which cooperate in such a way as to positively fix the operative position of said elements with respect to their longitudinal displacement in said retaining means.

2. Extendable antenna comprising a support, a plurality of rod-shaped elements extending in their operative position perpendicularly from said support, retaining means embracing said rod-shaped elements in which at least those of the elements that are mounted at both ends of said support are displaced longitudinally and fastening means lying adjacent to said rod-shaped elements with which said retaining means are secured to said support in such a way as to permit pivoting but not forward sliding thereof and which serve at the same time in operative position to clamp said rod-shaped elements in said retaining means and the latter to said support, whereby the said retaining means have recesses which receive said support when said rod-shaped elements are pivoted to their operative position, and means provided on said retaining means and on said rod-shaped elements which cooperate in such a way as to positively fix the operative position of said elements with respect to their longitudinal displacement in said retaining means and whereby the edges of said recesses embrace said support lying therein to a greater extent on one side than on the other side and the said retaining means are built in such a way that the distance between said retaining means and said support is limited in such a way that said rod-shaped elements can only be pivoted in one direction of rotation from their position parallel to said support to a position perpendicular to said support, and inversely.

3. Extendable antenna comprising a support, a plurality of rod-shaped elements extending in their operative position perpendicularly from said support, retaining means embracing said rod-shaped elements in which at least those of the elements that are mounted at both ends of said support are displaced longitudinally and fastening means lying adjacent to said rod-shaped elements with which said retaining means are secured to said support in such a way as to permit pivoting but not forward sliding thereof and which serve at the same time in operative position to clamp said rod-shaped elements in said retaining means and the latter to said support, whereby the said retaining means have recesses which receive said support when said rod-shaped elements are pivoted to their operative position, and stopping means provided on said retaining means and on said rod-shaped elements which cooperate in such a way as to positively fix the operative position of said elements with respect to their longitudinal displacement in 'said retaining means and hold them in this position even before said retaining means are clamped to said support by said fastening means.

(References on following page) References Cited in the file of this patent 2,813,268 UNITED STATES PATENTS 2,891,296

369,143 White Aug. 30, 1887 504,717 Fanckboner Sept. 12, 1893 5 1,978,224 2,777,657 Zent Jan. 15, 1957 6 Fisher Nov. 12, 1957 Darde June 23, 1959 FOREIGN PATENTS France Nov. 16, 1954 

